UN plastic treaty must mind the people:Citizen science can assist citizen involvement in plastic policymaking

By 2024, the United Nations treaty to end all plastic pollution is set to join multilateral forces to act on plastic pollution. While involving citizens has the potential to improve policy implementation, legitimacy, and relevance, effective measures are currently lacking in plastic pollution policy. Here, we aim to build on existing praxis in the European Union and analyze current initiatives engaging citizens. We discuss these in a citizen science context and provide recommendations for an effective treaty. We find that current measures are inadequate, that policy impact is contingent on the policy phases and the input type, and we highlight opportunities for citizen science to support public access to policy influence. We recommend that the upcoming treaty ensures access throughout the policy process, that inputs are systematized and harmonized to increase application and policy uptake, and finally, consistent equity in participation for citizens affected by plastic pollution.